1. Field of the Invention
The present invention relates to an injection molding apparatus including a fixed platen, a movable platen, and an intermediate platen (rotary platen) positioned between the fixed platen and the movable platen, and an injection molding method.
2. Description of the Related Art
There have conventionally been known multilayer molded products composed of various combinations of resin molded components, such as a multilayer molded product in which a plurality of resin molded components made of different materials are combined, a multilayer molded product in which a plurality of resin molded components made of the same material are combined, a multilayer molded product in which a plurality of resin molded components made of materials of different colors are combined, a multilayer molded product in which a plurality of resin molded components made of materials of the same color are combined, etc. Also, various molding methods are known as methods for forming such a multilayer molded product, such as a method using a characteristic molding apparatus, a method using a characteristic mold, etc. Among such molding methods is a method of forming a multilayer molded product by mounting a fixed mold, a movable mold, and a rotary mold on a multilayer molding apparatus including a fixed platen, a movable platen, and an intermediate plate (rotary platen) positioned between the fixed platen and the movable platen.
Patent Document 1 (Unexamined Japanese Patent Application Publication No. 2006-168223) discloses a multi-material injection molding apparatus (multilayer molding apparatus) for forming a multi-material molded product (multilayer molded product) by using a molding unit comprising a fixed mold (fixed mold), a movable mold (movable mold), and a rotary mold (rotary mold) which rotates between the fixed mold and the movable mold. The multi-material injection molding apparatus includes: a first injection device (first injection unit) which connects with the fixed mold for injecting a melt material; a second injection device which connects with the movable mold for injecting a melt material; a rotary mold support unit which supports the rotary mold from the part of the fixed mold such that the rotary mold can freely rotate and freely move in the moving direction of the movable mold; and a compressing means (mold clamping unit) which compresses the fixed mold and the movable mold through the rotary mold.
Patent Document 2 (U.S. Pat. No. 7,488,167) discloses a closing unit (mold clamping unit) which includes: first and second platens (a fixed platen and a movable platen which of which may be whichever of the first and second platens) of which at least one is movable to the other; an intermediate plate (rotary platen) disposed between the first and second platens; a molding tool disposed between one of the first and second platens and the intermediate plate; a means which limits the move of a mold between the other of the first and second platens and the intermediate plate, and includes a dummy mold which is disposed between the other of the first and second platens and the intermediate plate and not used for forming a molded product; and at least one ejector (product push-out means) arranged in or on the intermediate plate.
Note that the parentheses in the above descriptions relating to Patent Document 1 and Patent Document 2 are given for mentioning the components, etc. of the present invention that are considered to be equivalent or similar to the components immediately before the parentheses for better understanding of the present invention, and are not meant to suggest that the components, etc. immediately before the parentheses are identical with the parenthesized components.    [Patent Document 1] Unexamined Japanese Patent Application Publication No. 2006-168223    [Patent Document 2] U.S. Pat. No. 7,488,167